Halnaker Crossroads is a stop on the number 55 bus service from Chichester to Tangmere. The service runs half-hourly Mon-Sat and is seamlessly linked to (on-time) trains arriving from London. It then takes 21 minutes to Halnaker. On Sunday line 99A serves this route, but runs only every two hours.
Chichester station is on the London Victoria to Southampton West Coastway Line. Journey times (two trains an hour) are between 88 and 94 minutes Monday to Saturday and 106 or 113 minutes on Sunday.

Saturday Walkers’ Club: Take the train closest to 9.30 hours (but earlier if aiming for the late lunch pub in Singleton).

7 out of 10 (with several steep ascents around lunch, so may feel tougher than that)

Walk Notes

This strenuous West Sussex walk makes for a long day out, as it involves a bus connection on the way out after an already long train journey to Chichester. Its main purpose is to explore the scenic steep chalk downlands well north of Chichester around the Upper Lavant Valley, between St. Roche’s Hill and the South Downs chain, while enabling a visit to Cass Foundation’s Sculpture Park (on an extension) in the morning, and passing through the Goodwood estate as well as through Chichester’s Old Town at the end. The lonely grassy or wooded hillsides of the beautiful Lavant Valley are dissected by quiet flat bottomed valleys, and feature several pretty villages, as well as providing for stunning views.
Most of the climbing is done between the lunch pubs, but the longest ascent comes straight after the late lunch option, up to St. Roche’s Hill, from whose treeless summit you have grand views in all directions.
A very short Cass Sculpture Park-only walk, ending back in Halnaker, can be combined with out-and-backs to Halnaker Hill (with its windmill) and/or Boxgrove Priory, to make it a full day out.

Options

An Extension to Cass Sculpture Park adds - at least - 4.4 km and 109/112m ascent/descent. Budget 2 hours out and back. This is just about doable in combination with the full walk and that extended walk would be rated 10/10.
A Shortcut around lunch reduces the length of the walk by 3.6 km and the ascent/descent by 167m (rated 5/10).
Another Shortcut around lunch reduces the length of the walk by 0.8 km and the ascent/descent by 93m (rated 6/10).
An Alternative Ending in West Dean cuts out 6.5 km (rated 6/10).
A Cass Sculpture Park only-walk, returning to Halnaker for the bus to Chichester, would be 8.1 km long. This can be combined with one or other or both of the following out and backs:
Out-and-backs at the start to Halnaker Hill or Boxgrove Priory add 5.1 and 2.6 km respectively.
An infrequent bus service (number 99 Mon-Sat, 99A Sundays) runs past the early lunch stops in East Dean and Charlton. You need to phone ahead to book a stop though (01903-264 776)!
A half-hourly bus service runs from Singleton, West Dean and Lavant to Chichester (Mon-Sat only).
A half-hourly bus service from the fringes of Chichester cuts 2.5 km at the end (Mon-Sat only, last bus at 18.39 hours).

Lunch

The Anglesey Arms at Halnaker, Halnaker, Chichester, West Sussex, PO18 0NQ (01243 773 474). Open 12.00-24.00 Mon-Sat and 12.00-22.30 Sun. Food served 12.00-14.30 and 18.30-21.30 Mon-Sat and 12.00-17.00 Sun. Located at the start of the walk, it is the lunch stop on a Sculpture Park-only walk. It would then come after 8.1 km (5.0 mi) of walking.
The Star and Garter, East Dean, West Sussex, PO18 0JG (01243 811 318). Open 12.00-15.00 & 18.00-23.00 Mon-Fri and 12.00-23.00 Sat-Sun. Food served 12.00-14.30 & 18.00-22.00 Mon-Fri and 12.00-16.00 & 18.00-22.00 Sat-Sun. The Star and Garter is located 5.6 km (3.5 mi) into the walk and is a flint and brick country pub with rooms.
The Fox Goes Free, Charlton, West Sussex, PO18 0HU (01243 811 461). Open 11.00-23.00 Mon-Sat and 12.00-22.30 Sun. Food served 12.00-14.30 & 18.15-21.30 Mon-Fri and 12.00-21.30 Sat-Sun. Bar food served all day. The Fox Goes Free is located 9.4 km (5.9 mi) into the walk on Shortcut II and is a 400 year old inn with home cooked food.
The Partridge Inn, Singleton, West Sussex, PO18 0EY (01243 811 251). Open 12.00-23.00 Mon-Sun. Food served 12.00-14.30 & 18.00-21.00 Mon-Fri and 12.00-22.30 Sat and 12.00-17.00 & 18.15-21.30 Sun. The Partridge Inn is located 11.4 km (7.1 mi) into the full walk and is a 16th century pub with great character.